1. Field of the Invention
The present invention relates to a camera and, more particularly, to a camera featuring watertightness.
2. Related Art Statement
Cameras featuring a low-level watertightness, or daily-life level watertightness, are in widespread use. Most of the cameras featuring the daily-life level watertightness employ rubber formed in a ring gasket around the periphery of a film loading rear lid. The rubber gasket is pressed and then deformed by the rear lid when it is closed. With the rubber gasket in a tight engagement with the rear cover, water and light are blocked.
FIG. 12 is a cross-sectional view showing a profile of a peripheral edge of the rear lid and its associated components. The rear lid 20 has a U-shaped groove 20a into which a lid rubber gasket 21 to be described later is fastened with an adhesive. The rear lid 20 is seated onto a rear cover 22 with a clearance kept therebetween. A step 20b is formed on the rear lid 20.
Formed on the rear cover 22 are an abutment face 22a which the edge of the lid rubber gasket 21, when pressed, is deformed thereagainst to be put into tight engagement therewith, and a step 22b on which the rear lid 20 is supported with a gap kept therebetween. The lid rubber gasket 21 has an edge 21a which is deformed by and is put into tight engagement with the abutment face 22a of the rear cover.
The step 20b of the rear lid and the 22b of the rear cover conventionally reduces light rays that enter through the gap between the rear cover and the rear lid and reach the edge 21a of the lid rubber gasket.
To fully block water and light in the conventional camera, preferably the rubber is much deformed to increase the contact pressure with the rear lid, but the amount of deformation of the rubber is not so great so as to overpower the force required to close the rear lid. The use of the rubber may block water, but cannot fully block light. For this reason, outside the engagement portion of the rubber gasket, the rear lid and the rear cover which the rear lid is snapped into are matingly shaped in one form or another, such as with the step as described above.
The arrangement of the mating portion or a step presents difficulty in implementing a compact design. To realize a compact camera, watertightness and lighttightness must be assured using structure other than a matingly shaped portion.